Wastegate and Boost Creep FAQ

Boost and Wastegate Creep FAQ

Wastegate creep is a very common fault on the 2 port solenoid system, on both modded and standard cars. The most common cause is a lazy or dirty 2 port solenoid. What this does is reduce the bleed rate through the solenoid which allows the pressure in the system to build up enough for wastegate actuator to creep open this reduces boost.

Wastegate and Boost FAQ: A aftermarket external wastegate on a Subaru STi.

Then, the wastegate will close again the boost will increase again and the wastegate will creep open again and so on. In this situation a simple cleaning of the solenoid would normally cure the fault. The symptoms of this fault are lumpy, flat, and hesitant boost.

On a manual car wastegate creep will feel like the the car is pulling then backing off repeatedly like a surging effect while you are accelerating. This issue can also be caused by a poorly setup boost controller or a weak actuator spring. I have yet to come across a weak spring but it can happen.